Combination centrifugal-turbine pump



NOV. 22, C O

COMBINATION CENTRIFUGAL-TURBINE PUMP 7 Sheets-Sheet 1 Filed May 19, 1949 INVENTOR. L60 C [0575 BY 441%, W final la Ida tau gffq Filed May 19. 1949 Nov. 22, 1955 L. C. ROTH COMBINATION CENTRIFUGAL-TURBINE PUMP 7 Sheets-Sheet 2 rdiuau BY 4:10am duzzuu NOV. 22, 1955 1 Q ROTH COMBINATION CENTRIFUGAL-TURBINE PUMP 7 Sheets-Sheet 3 Filed May 19, 1949 bmw Nov. 22, 1955 ROTH COMBINATION CENTRIFUGAL-TURBINE PUMP 7 Sheets-Sheet 4 Filed May 19, 1949 I N VEN TOR. 6/ L60 CZ 501 /2 ixZZZlu 1012441;

'7 Sheets-Sheet 5 Filed May 19, 1949 m h y I QQ mm 4 M l \fi III Q 3 R My mm W I 6 an M Nov. 22, 1955 L. c. ROTH 2,724,338

COMBINATION CENTRIFUGAL-TURBINE PUMP Filed May 19, 1949 7 Sheets-Sheet 6 I N VEN TOR.

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COMBINATION CENTRIFUGAL-TURBINE PUMP Filed May 19, 1949 '7 Sheets-Sheet '7 INVENTOR. Z60 C Jfoih BY M, flldl'du llddw Patented Nov. 22, 1955 COMBINATION CENTRIFUGAL-TURBINE PUMP Leo C. Roth, Molina, Ill., assignor to Roy E; Roth Company, Rock Island, 111., a corporation of Illinois Application May 19, 1949, Serial No. 3 4,070

1 Claim. (31. 103-96 This invention relates, in general, to new and useful improvements in pumps, and is particularly concerned with a combination centrifugal-turbine pump.

While the particular embodiments of the invention which I shall describe hereinafter in connection with the drawings are particularly adapted for use in handling boiling liquids, it is to be understood that the. pumps of the present invention are not limited to such use, but may be employed for other purposes as suitable or desired.

Prior attempts have been made to combine two types of pumps into one and to operate themin unison. How ever, previous attemptsto provide a combination centrifugal-turbine pump have been directed along the line of providing two separate stages, onecentrifugal and one turbine, with a setof impeller vanes or blades for the centrifugal stage and a separate set of impeller vanes or blades for the turbine stage.

None of these prior two stage pumps have been concerned with obtaining improved ability to handle boiling liquids, and all of them have involved coupling together the separately acting sets of impeller vanes or blades and other complications in the construction and arrangement of the parts of the pump.

One of the main objects of the present invention is to provide an improved centrifugal-turbine pump which, with a small static suction head, will have the ability to handle boiling liquids with increased efficiency, and, more particularly, with generally the same efficiency as nonboiling liquids.

Another object of the invention is to provide a centrifugal-turbine pump which will have the ability to handle larger volumes of liquids at lower headswith greater eficiency than the conventional turbine pump.

Another object of the invention is to combine the centrifugal and turbineactions in a pump of only one stage, with the same impeller vanes or blades which act to produce the centrifugal action also acting to produce the turbine action, and without providing and coupling together separately acting sets of impeller vanes or blades; also without other complications in the construction and arrangement of the parts of the pump.

Another and more specific object of the invention is to provide a centrifugalturbine pump in which the centrifugal action and the turbine action are both produced in a common plane disposed radially of the axis of the impeller and within the same 360 rotatio'nof the impeller.

Another object of the invention is to provide a centrifugal-turbine pump having various features of novelty and advantages, and which is characterized by its simplicity in construction, its economy in manufacture, and its effectiveness in use with new and beneficial results which will hereinafter appear. 3

Further objects and advantagesof the, invention will appear from the following detailed description, taken in connection with the accompanying drawings which show the construction and operation of a number of illustrative embodiments of the invention.

In the drawings:

Figure l is a fragmentary transverse vertical sectional view through a pump embodying the present invention, taken substantially on the line 1-l of Figure 2;

Figure 2 is a sectional view, taken substantially on the line 22 of Figure 3;

Figure 3 is a transverse vertical section similar to Figure, 1 but with the impeller removed and portions of the inlet and outlet projections of the pump in elevation;

Figure 4- is an end view of another form of pump embodying the present invention, with the impeller removed;

Figure 5 is a vertical sectional view taken substantially on the line 5--:'i of Figure 4;

Figure 6 is a horizontal sectional view taken substantially on the line 66 of Figure 5;

Figure 7 is an end view, with the impeller removed, of another form of pump embodying the present invention;

Figure -8 is a horizontal sectional view taken substantially on the line 8% of Figure '7;

Figure 9 is a vertical sectional view taken substantially on the line 9 9 of Figure 7;

Figure 10 is a vertical sectional view taken substantially on the line ill-ll) of Figure 9;

Figure ll is an end view, without the impeller, of a further embodiment of the invention;

Figure 12 is a horizontal sectional view taken substantially on the line 12-12 of Figure 11;

Figure 13 is a fragmentary face view of the impeller shown in Figure 12;

Figure 14 is an inside elevational view of the head of the pump shown in Figures ll and 12; and

t Figure 15 is a vertical sectional viewtaken substantially on the line l5l5 of Figure 14.

With reference now to the drawings, the pump shown in Figures 1, 2, and 3 is a centrifugal-turbine pump comprising a pump casing indicated in its entirety at 1, and formed of two contiguous sides or casing parts 2 and 3.

The casing part 3 has a cylindrical part which fits snugly at 4 within the casing part 2. The casing parts 2 and 3 are connected by contiguous outwardly extending flanges 5 and 6 held together, for example, by suitable bolts or the like (not shown). The flanges 5 and 6 are of generally annular form, and the casing part 2 has a second outwardly extending flange '7.

The casing part 2 has an outwardly extending tubular boss 3 in which may be disposed suitable packing (not shown) to prevent leakage between the casing part 2 and the rotary pump shaft 9. An impeller or rotation element lli is fixed on the shaft 9, for example, by a key or spline 11 for rotation with the shaft. The impellet it has two sets of vanes or blades 12. One set of vanes LlIZopens from one side of theouter marginal portion of the impeller, and the other set ofvanes 12 opens from the other side of the outer marginal portion of the impeller. Both sets of these vanes 12'; open radially from the outer periphery of the impeller.

The casing part 2 has a liquid inlet projection 13 and a liquid outlet projection l t. The inlet projection 13 extends substantially tangentially to the casing, while the outlet projection Lt extends substantially radially from the casing.

The inner sides of the casing parts 2 and 3 have op posed ribs 15 presenting sealing surfaces 16 which cooperate With the opposite sides of the impeller Ill and, as shown in Figure 2, define the pressure developing channel or passageway 1'7 of the turbine part of the pump. As shown in Figure 3, these ribs to or sealing surfaces 16 extend from position adjacent to the far side ol' the outlet 13 in the direction of rotation of the imeller inwardly toward the axis of the opening through which the pump shaft 9 extends. The inner ends of the ribs 15 or sealing surfaces 16 are curved or roundedat 19 partially around the axis of the opening through which the pump shaft 9 extends and in suitable spaced relation thereto.

The ribs or sealing surfaces 16 terminate in position indicated at 20 in Figure 3. As viewed in Figure 3, the space within the pump casing clockwise of the ends 20 of the ribs 15 or sealing surfaces 16 constitutes the centrifugal part of the pump. The space within the pump casing counterclockwise of the ends 20 of the ribs 15 or sealing surfaces 16 and to the outlet 18, as the pump is viewed in Figure 3, constitutes the turbine part of the pump. It will be noted that the centrifugal and turbine parts of the pump are both arranged in a common plane disposed radially of the axis of the impeller and within the same 360 rotation of the impeller. Moreover, as will presently appear, the same impeller vanes or blades 12, which act to produce the centrifugal action along the centrifugal part of the pump, also act to produce the turbine action along the turbine part of the pump.

The particular configuration of the ribs 15 or sealing surfaces 16, and the particular locations at which the ends 20 thereof terminate, may vary widely within the scope of the present invention. For example, the centrifugal portion of the pump may extend through about onefourth, one-third, one-half, or any other part of the 360 rotation of the impeller, with the turbine part of the pump extending through substantially the remaining or any other desired part of such 360 degrees.

The interior of the inlet projection 13 opens into the inlet end of the passageway 17 at the beginning of the centrifugal part of the pump through an opening 21 formed in the casing parts as a continuation of the interior of the inlet projection 13. The outlet 18 opens from the outlet end of the passageway 17 at the end of the turbine part of the pump into a receiving or separating chamber 22 in the outlet projection 14. The chamber 22 has an outlet or discharge opening 23 through which the liquid is delivered from the pump.

A centrifugal baffle 24 is preferably placed across the suction of the pump, for example, by forming the bafile integral with the casing part 2 and in position extending across the inlet opening 21 as shown, described, and claimed in my copending application Serial No. 71,922, filed January 21, 1949. The particular centrifugal baffie 24 illustrated in the drawing is shown of tapered form, with its tapering sides 25 converging outwardly to a relatively sharp edge within the pump inlet. The inner face 26 of the baffle 24 is shown of generally concave form and spaced radially outwardly from the outer periphery of the impeller 10 to provide a free channel at 27 for directing the centrifugally hurled liquid down into the adjacent end of the channel or passageway 17 of the pump under pressure generated by centrifugal force.

In the operation of the pump, the impeller 10 is caused to rotate. The liquid enters the pump suction, is divided by the centrifugal deflector 24, and flows toward the center and toward the sides of the impeller 10 in the first section of the pump which is centrifugal. The direction of admission of the liquid is shown by the arrows a in Figure 3. The arrows b show, in general, how the centrifugally hurled liquid, instead of being directed toward the pump suction and impinging on the liquid entering the suction of the pump, with harmful or deleterious results, strikes the inner surface of the deflector 24 and is directed down into the inlet end of the channel or passageway 17.

As the incoming liquid is engaged by the impeller vanes 12, it is hurled outwardly and generally in the direction of impeller rotation by centrifugal force. This liquid, in motion, impinges on the centrifugal deflector face and on the outermost wall of the centrifugal casing. From here it is directed by the casing outer walls and under a pressure generated by centrifugal force into the entrance of the turbine part of the pump which begins as the liquid passes the ends 29 of the ribs 15 or sealing surfaces 16 in the direction of impeller rotation.

The turbine action, which begins as the liquid passes the ends 20 of the ribs 15 or sealing surfaces 16, consists of a centrifugal push of the liquid to the periphery of the channel 17 at the turbine part of the pump, and a recirculation toward the root of the impeller vanes 12 repeated over and over, as indicated generally by the arrows c in Figure 2. Each of these recirculations imparts energy to the liquid, which results in static pressure. I

From the foregoing description and the drawings, it will be apparent that, instead of being delivered into the channel 17 of the turbine part of the pump only by the static suction head which is available as in the con ventional turbine pump, the liquid is forced centrifugally into the restricted channel at the turbine part of the pump. Undue restriction at the inlet to get a pressure building effect is avoided. Instead, the liquid enters a relatively large and unrestricted inlet at the beginning of the centrifugal part of the pump, and is then forced centrifugally into the relatively restricted channel at the turbine part of the pump. As a result, there is a more gradual application of pressure to the liquid, and the velocity of the liquid entering the turbine part of the pump is increased without lowering the absolute pressure. The ribs 15 or sealing surfaces 16 prevent by-pass of the liquid from the high pressure area to the low pressure area of the pump.

I have found that a pump according to the present invention has the ability to handle boiling liquid with higher efficiency, and, more particularly, with the same efliciency as non-boiling liquids (this presupposes a small static suction head). This is the result of large suction openings which enable the liquid to flow into the pump as fast as it can be pumped out. Once the liquid is engaged by the impeller vanes, there is never any removal of liquid faster than the ability of a small static suction head to force liquid in to replace it, thus reventing vaporization due to lowering absolute pressure. Once the liquid is engaged by the impeller vanes, it is always under pressure and there are no low-pressure orcavitation pockets in the pump.

The simplicity and improved arrangement of the parts of the pump are due to the combination of the centrifugal and turbine actions in a pump of only one stage and with the same impeller vanes acting at the centrifugal part and also at the turbine part of the pump. The production of the centrifugal action and the turbine action in a common plane disposed radially of the axis of the impeller and within the same 360 rotation of the impeller also provides for simplicity in construction and improved arrangement of the parts of the pump.

The improvements of the present invention definitely improve the efliciency of the pump and provide a combination centrifugal-turbine pump which will not lose capacity in handling boiling liquids at low heads. Ordinarily, centrifugal pumps will not handle boiling liquids at low heads at the same volumes with the same static suction heads as they will handle cold or non-boiling liquids, while turbine pumps do not have the efiieiency of the pumps of the present invention, particularly for the purposes set forth.

From the drawings and the foregoing description, it will be apparent that the pump shown in Figures 1, 2, and 3 has an impeller 10 with vanes or blades 12 on both sides, and liquid channels on both sides of the impeller. The pump shown in Figures 1, 2, and 3 also incorporates a centrifugal deflector as shown and described, and its suction enters the pump at the impeller periphery.

As will presently appear, the pump shown in Figures 4, 5, and 6 has the suction opening in the end or center of the pump, with vanes or blades on only one side of the impeller, and a liquid passage on only one side of the impeller.

With reference now to Figures 4, 5, and 6, the pump shown in these figures comprises a pump casing indicated in its entirety at 28 andformed of two contiguous sides or casing parts 29 and 3:0.

The casing part 30 has a cylindrical part which fits snugly at 31 within the casing part 29. The casing parts 29 and 30 are connected by contiguous outwardly extending flanges 31 and 32 held together, for example, by suitable bolts 33. The flanges 331 and 32 are of generally annular form, and the casing part 29 has a second outwardly extending flanged l.

The casing part 29 has an outwardly extending tubular boss 35 in which may be disposed suitable packing (not shown) to prevent leakage between the casing part 29 and the rotary pump shaft 36. An impeller or rotation element 37 is fixed on the shaft 36, for example, by a key or spline 38 for rotation with the shaft. The impeller 37 has one set of vanes or blades on only one side of the impeller. The vanes or blades 39 open from one side and radially from the outer periphery the impeller.

The casing part 3t has a liquid inlet db which enters the pump in the end or at the center or axis of the pump. The liquid outlet projection d1 extends substantially radially from the casing and is spaced from the plane of rotation of the impeller in a generally axial direction. As in the embodiment of the invention illustrated in Fig-- ures 1, 2, and 3, the vanes or blades 39 of the pump shown in Figures 4, 5, and 6, extend to the periphery ofthe impeller 37, and the liquid channel 413 extends beyond the impeller periphery.

The inner side of the casing part 36 has a rib l3 presenting a sealing surface 44 which cooperates with the adjacent side of the impeller 37. As shown in Figure 4, the rib 43 or sealing surface extends from position adjacent to the far side of the outlet 45 in the direction of rotation of the impeller (indicated by the arrow 46 in Figure 4) inwardly toward the axis of the opening through which the pump shaft 36 extends. Near its inner end the rib 43 or sealing surface 44 is curved or rounded around the axis of the opening through which the pump shaft 36 extends and in suitable spaced relation thereto.

The rib or sealing surface 44 terminates in position indicated at 47 in Figure 4. As viewed in Figure 4, the space within the pump casing clockwise of the end 47 of the rib 4-3: or sealing surface 44 constitutes the centrifugal part of the pump, as indicated in Figure 4 by the arcuate line 48, with the arrow heads at opposite ends thereof. The space within the pump casing counterclockwise of the end 47 of the rib 43, as the pumpis viewed in Figure 4, constitutes the turbine part of the pump. As in the preceding embodiment of the invention, the centrifugal and turbine parts of the pump are both arranged in a common plane disposed radially of the axis of the impeller and within the same 36ll rotation of the impeller. Moreover, as in the preceding embodiment of the invention, the same impeller vanes or blades 3?, which act .toproduce the centrifugal action along the centrifugal part of the pump, also act to produce the turbine action along the turbine part of the pump.

As with the precedingembodiment of the invention, the particular configuration of the rib 53 or sealing surface 44, and the particular location at which the end 4? thereof terminates, may vary widely within the scope of the present invention.

In the operationof the pump shown in Figures 4, 5, and 6, the impelleril'i' is caused to rotate. The liquid enters the pump suction 40 and flows toward the blades 39 of the impeller. The direction of admission of the liquid is shown by the arrows cl in Figures 5 and 6. The arrows e show, in general, how the centrifugally hurled liquid is directed down into the inlet end of the channel or passageway 42.

As the incoming liquid is engaged by the impeller blades 3b, it is hurled inthe direction of impeller rotation by centrifugal force. This liquid, in motion, impinges on the outermost wall of the centrifugal casing. From here, it is directed by the casing outer walls and under pressure generated by centrifugal force into the entrance of the turbine part of the pump which begins as the liquid passes the end 47 of the rib 43 in the direction of impeller rotation.

The turbine action, which begins as the liquid passes the end 47 of the rib 43, consists of a centrifugal push of the liquid to the periphery of the channel 42 at the turbine part of the pump and a recirculation toward the root of the impeller blades 39 repeated over and over, as indicated generally by the arrows f in Figures 4, 5, and 6. Each of these recirculations imparts energy to the liquid, which results in static pressure. As the liquid reaches the outlet passage 49 (Figure 5), it passes through this passage to the outlet 45, from which outlet 45 it is discharged from the pump.

As in the preceding embodiment of the invention, the liquid, instead of being delivered into the channel 42 at the turbine part of the pump only by the static suction head available as in the conventional turbine pump, is forced centrifugally into the restricted channel at the turbine part of the pump. Undue restriction at the inlet to get a pressure building effect is avoided, and as before, the liquid enters a relatively large and unrestricted inlet at the beginning of the centrifugal part of the pump, and is then forced centrifugally into the relatively restricted channel at the turbine part of the pump. As before, there is a gradual application of pressure to the liquid, and the velocity of the liquid entering the turbine part of the pump is increased without lowering the absolute pressure. The rib 43 or sealing surface 44 prevents bypass of the liquid from the high pressure area to the low pressure area of the pump.

As before, once the liquid is engaged by the impeller vanes, it is always under pressure, and there are no lowprcssure or cavitation pockets in the pump. Also, as before, the production of the centrifugal action and the turbine action in a common plane disposed radially of the axis of the impeller and within the same 350 rotation of the impeller provides for simplicity in construction and improved arrangement of the parts of the pump.

The form of pump shown in Figures 7, 8, 9, and 10 of the drawings has an impeller wisetnavhorfikbv both sides, and liquid channels on both sides of the impeller, as in the embodiment of the invention shown in Figures 1, 2, and 3. In the pump of Figures 7, 8, 9, and l0, however, the suction or inlet enters in the end or at the center or axis of the pump.

Wtih reference now to Figures 7 8, 9 and 10, the pump shown in these figures comprises a pump casing indicated in its entirety at 50 and formed of two contiguous casing parts 50 and Bl. The casing part 51 has a cylindrical part which fits snugly at 52 within the casing part 50. The casing parts 51? and 51 are connected by contiguous outwardly extending flanges 53 and 54 held together, for example, by suitable bolts 55. The flanges $3 and 54 are of generally annular form.

The casing part till has an outwardly extending tubular boss 56 in which may be disposed suitable packing (not shown) to prevent leakage between the casing part 5b and the rotary pump shaft 57. An impeller or rotation element 58 is fixed on the shaft 57, for example, by a key or spline 5'9 for rotation with the shaft. The impeller has two sets of vanes or blades db. ()ne set of blades 6t opens from one side of the outer marginal portion of the impeller, and the other set of blades 69 opens from the other side of the outer marginal portion of the impeller. Both sets of blades 60 open radially from the outer periphery of the impeller.

The casing part 51 has a liquid inlet 61 which enters the pump in the end or at the center or axis of the pump. The liquid outlet projection 62 extends substantially radially from the pump casing.

The inner sides of the casing parts 50 and 51 have opposed ribs 63 presenting sealing surfaces 64 which cooperate with the opposite sides of the impeller 58, and, as shown in Figures 8 and 9, define the pressure developing channel 65 along the centrifugal and turbine parts of the pump. As shown in Figure 7, the ribs 63 or sealing surfaces 64 extend from position adjacent to the far side of the outlet 65' in the direction of rotation of the impeller 58 toward the axis of the opening through which the pump shaft '7 extends. The inner ends of the ribs 63 are curved or rounded at 66 partially around the axis of the opening through which the pump shaft 57 extends, and in suitable spaced relation thereto.

The ribs 63, or sealing surfaces 64, terminate in position indicated at 67 in Figure 7. The space within the pump casing clockwise of the ends 67 of the ribs 63 constitutes the centrifugal part of the pump. The space Within the pump casing counterclockwise of the ends 67 of the ribs 63 to the outlet 65 as the pump is viewed in Figure 7 constitutes the turbine part of the pump. As before, the centrifugal and turbine parts of the pump are both arranged in a common plane disposed radially of the axis of the impeller and within the same 360 rotation of the impeller. Moreover, as before, the same impeller vanes or blades 69, which act to produce the centrifugal action along the centrifugal part of the pump, also act to produce the turbine action along the turbine part of the pump. The circumferential extent of the centrifugal part of the pump and the circumferential extent of the turbine part of the pump may vary within the scope of the present invention.

The suction of the pump is provided with a centrifugal baffle 68. The baffle 68 is positioned at the inlet or suction of the pump, for example, by forming it integral with the casing part 50, and in position extending across andspaced outwardly from the periphery of the impeller 58. The baflle 68 is shown as having a generally concave inner space 69 spaced radially outwardly from the outer periphery of the impeller 58 to provide a free channel 70 for directing the centrifugally hurled liquid down into the adjacent end of the channel or passageway 65 of the pump under pressure generated by centrifugal force. The bathe is shown of a width greater than the width of the impeller, with the inner face of the baflie completely covering and extending beyond the opposite sides of the periphery of the impeller. The Width of the baffle 68 may vary within the scope of the present invention.

In the operation of the pump shown in Figures 7, 8, 9 and 10, the impeller 58 is caused to rotate. The liquid enters the pump suction, is divided by the centrifugal defiector 68, and flows toward the opposite sides of the impeller. The direction of admission of the liquid is shown by the arrows h in Figure 8. The arrows i Show, in general, how the centrifugally hurled liquid strikes the inner surface of the deflector 68 and is directed down into the inlet end of the channel or passageway 65.

As the incoming liquid is engaged by the impeller vanes 60, it is hurled outwardly and generally in the direction of impeller rotation by centrifugal force. This liquid, in motion, impinges on the centrifugal deflector face 69 and on the outermost wall of the centrifugal casing. From here, it is directed by centrifugal force into the entrance of the turbine part of the pump which begins as the liquid passes the ends 67 of the ribs 63 in the direction of impeller rotation.

The turbine action, which begins as the liquid passes the ends of the ribs 63, consists of a centrifugal push of the liquid to the periphery of the channel 65 at the turbine part of the pump, and a recirculation toward the root of the impeller vanes 68 repeated over and over, as indicated generally by the arrows k in Figure 8. Each. of these recirculations imparts energy to the liquid, which results in static pressure.

As in the preceding embodiments of the invention, the

liquid, instead of being delivered into the channel 65 of the turbine part of the pump only by the static suction head which is available as in the conventional turbine pump, is forced centrifugally into the restricted channel at the turbine part of the pump. As in the preceding embodiments of the invention, undue restriction at the inlet to get a pressure building effect is avoided, and the liquid enters a relatively large and unrestricted inlet at the beginning of the centrifugal part of the pump and is then forced centrifugally into the relatively restricted channel at the turbine part of the pump. As a result, there is a more gradual application of pressure to the liquid, and the velocity of the liquid entering the turbine part of the pump is increased without lowering the absolute pressure. The ribs 63 prevent by-pass of the liquid from the high pressure area to the low pressure area of the pump.

The pump shown in Figures 1l-15 has the suction opening in the end or center of the pump, with blades or vanes on only one side of the impeller; also a liquid passage on only one side of the impeller. The impeller blades of this embodiment of the invention do not extend to the impeller periphery, and the outside diameter of the liquid channel is the same as the outside diameter of the impeller blades.

Referring now to Figures 11-15, the pump shown in these figures comprises a pump casing indicated in its entirety at 71 and formed of two contiguous casing parts 72 and 73. The casing part 73 has a cylindrical part which fits snugly at 74 within the casing part 72. The casing parts 72 and 73 are connected by contiguous outwardly extending flanges 75 and 76 held together, for example, by suitable bolts 78. The flanges 75 and 76 are of generally annular form, and the casing part 72 has a second outwardly extending flange 79.

The casing part 72 has an outwardly extending tubular boss 80 in which may be disposed suitable packing (not shown) to prevent leakage between the casing part 72 and the rotary pump shaft 81. An impeller or rotation element 82 is fixed on the shaft 81, for example, by a key or spline 83 for rotation with the shaft. The impeller 82 has one set of blades or vanes 84 on only one side of the impeller. The blades 84 do nottextend to the impeller periphery, and the outside diameter of the liquid channel 85, which is on only one side of the impeller, is the same as the outside diameter of the impeller blades 84. The outer ends of the impeller blades 84 are closed by the annular impeller wall 86 which rotates in cooperation with the bore in the casing part 72.

The casing part 73 has a liquid inlet 87 which enters the pump in the end or at the center or axis of the pump. The liquid outlet projection 88 extends substantially radially from the casing part 73 and is spaced from the plane of rotation of the impeller in a generally axial direction.

The inner end of the casing part 73 has a rib 89 presenting a sealing surface 90 which cooperates with the adjacent side of the impeller 82. The rib 89 extends from position adjacent to the far side of the outlet 91 in the direction of rotation of the impeller (indicated by the arrow 92 in Figures 11 and 14) inwardly toward the axis of the opening through which the pump shaft 81 extends. Near its inner end the rib 89 is curved or rounded around the axis of the opening through which the pump shaft 81 extends, and in suitable spaced relation thereto.

The rib 89 terminates in position indicated at 93 in Figure 14. As viewed in Figure 14, the space within the pump casing counterclockwise of the end 93 of the rib 89, and to this rib, constitutes the centrifugal part of the pump. The space within the pump casing clockwise of the end of the rib 89, as the pump is viewed in Figure 14, constitutes the turbine part of the pump. As in the preceding embodiments of the invention, the

centrifugal and turbine parts of the pump are both arranged in a common plane disposed radially of the axis of the impeller and within the same 360 rotation of the impeller. Moreover, the same impeller vanes or blades 84, which act to produce the centrifugal action along the centrifugal part of the pump, also act to produce the turbine action along the turbine part of the pump.

In the operation of the pump shown in Figures 1115, the impeller 82 is caused to rotate. The liquid enters the pump suction 87, and flows toward the blades 34 of the impeller. The direction of admission of the liquid is shown by the arrows m in Figures 12 and 15. The arrows it show, in general, how the centrifugally hurled liquid is directed down into the inlet end of the channel or passageway 85.

As the incoming liquid is engaged by the impeller blades 84, it is hurled in the direction ofimpeller rotation by centrifugal force. This liquid, in motion, impinges on the wall 86 and the adjacent wall of the pump casing. From here, it is directed by the casing outer walls and by the impeller wall under pressure generated by centrifugal force, into the entrance of the turbine part of the pump which begins as the liquid passes the end 93 of the rib 89 in the direction of impeller rotation.

The turbine action, which begins as the liquid passes the end 93 of the rib 89, consists of a centrifugal push of the liquid to the periphery of the channel 85 at the turbine part of the pump and a recirculation toward the root of the impeller blades 84 repeated over and over, as indicated generally by the arrows in Figures 12 and 15. Each of these recirculations imparts energy to the liquid, which results in static pressure. As the liquid reaches the outlet 91, it passes through this outlet and is discharged from the pump.

The advantages described in connection with the preceding embodiments of the invention are obtained in substantially the same manner in the embodiment of the invention shown in Figures 11-15 and will not, therefore, be repeated.

The embodiments of the invention shown in the drawings are for illustrative purposes only, and it is to be expressly understood that said drawings and the accompanying specification are not to be construed as a definition of the limits or scope of the invention, refer- 4 ence being had to the appended claims for that purpose.

I claim:

A centrifugal-turbine pump comprising a pump casing having an inner periphery defining the outer periphery of an annular channel, said casing having a liquid inlet opening into said annular channel and a liquid outlet opening from said annular channel, an impeller rotatable in said casing, rib means integral with the interior of said pump casing and extending generally radially inwardly from said inner periphery of said pump casing and terminating at its inner end in a portion curved around the axis of said impeller toward said inlet but terminating at a free end spaced distance from the opening of said inlet into said annular channel to provide a relatively unrestricted centrifugal passageway extending circumferentially from the opening of said inlet into said annular channel toward said outlet and terminating at the free end of said curved portion of said rib means, said generally radially extending portion of said rib means extending completely to the inner periphery of said casing at position between. said inlet and outlet to separate said inlet from said outlet, said rib means in cooperation with the inner periphery of said casing defining a turbine passageway more restricted than said centrifugal passageway and extending circumferentially from said free end of said rib means to said outlet, and a centrifugal baflie at the inlet to said centrifugal passageway, said baffie having an inner face spaced outwardly from the periphery of the impeller and wider than the periphery of the impeller, with the inner face of the baflle completely covering and extending beyond opposite sides of the periphery of the impeller whereby to prevent liquid thrown outwardly by the impeller from impinging on and disturbing the free entrance of the liquid into the pump.

References Cited in the file of this patent UNITED STATES PATENTS 1,867,651 Burks July 19, 1932 2,042,499 Brady June 2, 1936 2,051,080 Frederick Aug. 18, 1936 2,056,553 Abramson a Oct. 6, 1936 2,340,747 Hansen Feb. 1, 1944 FOREIGN PATENTS 368,715 Germany Feb. 9, 1923 499,484 Germany June 6, 1930 608,126 Germany Jan. 16, 1935 873,329 France July 6, 1942 

